# Ikawa Line

The Ikawa Line (井川線, Ikawa-sen) is a railway line of the Ōigawa Railway. It runs from Senzu Station in Kawanehon, Shizuoka, the end station of the Ōigawa Main Line, and terminates at Ikawa Station in Aoi-ku, Shizuoka. The line has 61 tunnels and 51 bridges along its 25.5 kilometer length and includes the only rack-and-pinion railway section currently operating in Japan.
In September 2022, the Ōigawa Main Line suffered substantial damage from Tropical Storm Talas. Rail services between Kawane-Onsen Sasamado and Senzu Station were suspended until further notice. Steam locomotives were changed to only operate between Shin-Kanaya and Kawane-Onsen Sasamado. Ōigawa Railway advises customers intending to travel beyond Ieyama Station to the Ikawa Line, towards Senzu and the Sumata Gorge area, to transfer to Kawanehon Town's community buses at Ieyama Station, which provide connections to Senzu Station.

## History

The Ikawa line began operations on March 20, 1935, as a private line for the Ōigawa Electric Company, to carry workers and materials upstream to facilitate dam construction. The single track line was originally constructed with 762 mm (2 ft 6 in) narrow gauge; however, in order to have dual usage with carriages on the Senzu-Shinrin Line (now closed) a third rail was added the following year for the Japanese standard gauge (1,067 mm (3 ft 6 in)). In 1954, the line was extended under the aegis of the Chubu Electric Power Company to facilitate the construction of the Ōigawa Dam. Railway operations were spun out of Chubu Electric into a separate company in 1959, with the foundation of the Ōigawa Railway Company. With the completion of the Nagashima Dam, a portion of the line had to be re-routed along a 1.5 km section with a maximum gradient of 9% (~1 in 11). This required the installation of an Abt rack system on October 2, 1990. An automatic train stop system was installed at the end of March 2009.
The line runs through an isolated mountain area with no cities or towns, and has a very small population density. Most of the passengers are tourists visiting one of the hot spring resorts along the line, or alpinists and hikers heading for the peaks of the Southern Alps National Park.

### Former connecting lines

* Sawama station - the 762mm gauge Sen-to forest railway, consisting of a 36 km 'main line', branches 6 km and 4 km long and a 1.4 km cableway, operated between 1934 and 1968.

## Stations

| Name | Name | Distance (km) | Connections | Location | Location |
| Senzu | 千頭 | 0.0 | Ōigawa Railway Ōigawa Main Line | Shizuoka | Kawanehon, Haibara District |
| Kawane-Ryōgoku | 川根両国 | 1.1 | | Shizuoka | Kawanehon, Haibara District |
| Sawama | 沢間 | 2.4 | | Shizuoka | Kawanehon, Haibara District |
| Domoto | 土本 | 3.9 | | Shizuoka | Kawanehon, Haibara District |
| Kawane-Koyama | 川根小山 | 5.8 | | Shizuoka | Kawanehon, Haibara District |
| Okuizumi | 奥泉 | 7.5 | | Shizuoka | Kawanehon, Haibara District |
| Abt Ichishiro | アプトいちしろ | 9.9 | ( | Shizuoka | Kawanehon, Haibara District |
| Nagashima Dam | 長島ダム | 11.4 | | Shizuoka | Kawanehon, Haibara District |
| Hiranda | ひらんだ | 12.6 | | Shizuoka | Kawanehon, Haibara District |
| Okuōikojō | 奥大井湖上 | 13.9 | | Shizuoka | Kawanehon, Haibara District |
| Sessokyō Onsen | 接岨峡温泉 | 15.5 | | Shizuoka | Kawanehon, Haibara District |
| Omori | 尾盛 | 17.8 | | Shizuoka | Kawanehon, Haibara District |
| Kanzō | 閑蔵 | 20.5 | | Shizuoka | Aoi-ku, Shizuoka |
| Ikawa | 井川 | 25.5 | | Shizuoka | Aoi-ku, Shizuoka |
* Okuoi Rainbow Bridge
* Mountainous terrain
* Abt rack rail
* Oigawa ED903 rack locomotive